The present invention relates to absorbent products, such as an incontinence pad, a sanitary napkin, a panty liner and a disposable diaper for absorbing urine, menstrual blood, vaginal discharge and the like, that include a concave groove-shaped body fluid inflow portion for receiving a large amount of body fluid with an absorber.
Conventionally, as an absorbent product such as an incontinence pad, a sanitary napkin, a panty liner or a disposable diaper, an absorbent product is known in which an absorber formed of cotton-like pulp or the like is interposed between a liquid-impermeable back surface sheet such as a polyethylene sheet or a polyethylene sheet laminated non-woven fabric and a liquid-permeable front surface sheet such as a non-woven fabric or a liquid-permeable plastic sheet.
Among such absorbent products, in the case of an incontinence pad for a large amount in which a setting value for the amount of moisture absorbed exceeds 100 cc, since the incontinence pad needs to receive, at a time, a large amount of urine in a small area of a crotch portion, the incontinence pad is developed in which a concave portion is provided in order to promote the temporary storage of urine in the surface of the absorber and the diffusion thereof.
For example, Japanese Patent No. 3811000 discloses a disposable diaper which includes a liquid-permeable front surface sheet, a liquid-impermeable back surface sheet and an absorbent core interposed between both the sheets, in which the core is coated with an absorption diffusion sheet, in which at least one groove recessed in a direction extending from the surface sheet to the back sheet is formed in the core on the side of the surface sheet, in which the bottom portion and the side wall portion of the groove are covered with the surface sheet, in which the core contains a water-absorbent fiber and superabsorbent resin particles and in which the water-absorbent fiber and the superabsorbent resin particles are interposed between the surface sheet and the back surface sheet in the bottom portion of the groove.
Japanese Patent No. 3406214 discloses a disposable diaper in which along an imaginary line extending in a direction from a front waist region through a crotch region to a back waist region, at least a part of a core is divided, in which the core is formed with one fiber layer mainly made of pulverized pulp and one particle layer mainly made of superabsorbent resin particles, which is a substantially laminate product where the fiber layer is located on the particle layer and in which the particle layer is exposed to the side surface of the core in the divided portion.
Furthermore, Japanese Patent No. 3012472 discloses a disposable diaper in which an absorbent core is interposed between a liquid-permeable front surface sheet and a liquid-impermeable back surface sheet, which is formed, in a forward and backward direction, with a front body, a back body and a crotch region located therebetween and which includes a concave portion capable of storing feces in the crotch region of the core.